For the reclosability of bags and packagings a multitude of press-on closures and press-on closure tapes are known already. In most cases, these are press-on closure tapes produced by continuous extrusion, which consist of two strands. The two strands mostly are equipped with two or more hooks mutually engaging in each other.
In another type of press-on closure tapes, which are known from US 2003/0077008 A1, one strand has a groove provided with hooks, while the other strand engages in the groove with an arrowhead-like hook.
The integral forming of the press-on closures or press-on closure tapes with bags or packages also is known already.
Mounted in the bag openings, these closures are opened at the so-called gripping tabs by pulling them open and are closed by pressing them shut and stroking along them with thumb and index finger.
However, the prior art closures have the disadvantage that groove and hook tip or hook and double hook must come to lie precisely on top of each other for interlocking and must then be pressed into each other with some resistance, which mostly is very difficult to do for the user and often fails. Then, the bags or packages remain open, and the contents go bad or get dusty or are exposed to other negative environmental influences.
In particular in the case of food packages, where these closures are used to an increasing extent, this disadvantage is particularly disturbing, as after withdrawing parts of the contents, the remainder should be sealed and protected. Closing these closures is also made particularly difficult in that the grooves and hooks are very small, and they often cannot be brought in engagement precisely. Thus, correct closing requires some skill and good eyes.
In single households, mostly only small portions are consumed and therefore partial withdrawals are desired. In these cases, a possibility for reclosing is desired to a particular extent. On the other hand, these single households very frequently are inhabited by elderly people, who not only have lost a certain skill, but also have a deteriorated vision and then frequently do not get along with complicated closing operations.
To meet the currently frequently used requirement of the advertisement and packaging industry to provide some convenience for the consumers, a multitude of sealing bags with a slider, in particular made of plastics, at the top end of the bag or the package are being offered in the field of the reclosable bags and packages. For the consumer, these packages are easy to open and to close by simply moving the slider to and fro, but they have the disadvantage that they are very expensive and technically very complex to manufacture. Another disadvantage consists in that the sliders considerably increase the volume of the stacked bags, so that more packaging is required for these bags.
From EP 1 431 203 A1, a press-on closure tape having a groove member is known. The groove member includes funnel-shaped webs with inwardly pointing projections. The funnel-shaped expansion of the groove member should ensure that upon closing the press-on closure tape the engagement element can safely get into the groove, and in particular also when the engagement element and the groove initially are not yet correctly positioned with respect to each other. However, if the engagement element is pressed in with too much inclination, a part of the press-on closure tape lying beside the engagement element first can impinge on the tip of one of the funnel-shaped webs and prevent the engagement element from smoothly sliding into the groove. Only an increased pressure will then effect interlocking with the groove.
It is an object of the present application to avoid this disadvantage and create a press-on closure or a press-on closure tape, which can be closed even more easily and reliably.
This object may be achieved by a press-on closure, optionally made of plastics, comprising at least one groove member having a groove, which has funnel-shaped webs with inwardly pointing projections (14, 15), and at least one engagement member (7) having an engagement element (8), wherein on each side of the engagement element a supporting post is provided The supporting posts can achieve the effect that the engagement element always impinges substantially straight on the funnel-shaped webs of the groove member. The supporting posts prevent or reduce the likelihood of an inclined position of the engagement element by supporting the same on both sides. The handling of the press-on closure tape thereby is made even more reliable.
Various additional advantageous embodiments may also be achieved.
For example, in one example, the supporting posts extend parallel to the engagement element.
Furthermore, the supporting posts preferably are slightly shorter than the engagement element. If the supporting posts were just as long or longer than the engagement element, the press-on closure tape no longer could be closed reliably or could not be closed at all. On the other hand, when the supporting posts are too short, they can perform their function only insufficiently or not at all. Preferably, the supporting posts are about 2% to 20% shorter than the engagement element, more preferably about 3% to 10%, even more preferably about 5% to 6% shorter than the engagement element.
The reclosable bag or the reclosable packaging examples described herein, which may be made of plastics, such as polyethylene or polypropylene, are characterized by an inventive press-on closure or an inventive press-on closure tape. The reclosable bag or the reclosable packaging and the press-on closure or the press-on closure tape can be formed integrally.